Writing instrument



FIG. 1 is an elevational view, with the writing instrument rotated approximately 45 degrees along its long axis from the position shown in FIG. 2;

FIG. 2 is a front elevational view;

FIG. 3 is a right side elevational view, the left side being a mirror image thereof;

FIG. 4 is a rear elevational view;

FIG. 5 is a top plan view; and,

FIG. 6 is a bottom plan view. 

What claimed is the ornamental design for the writing instrument, as shown and described. 